<!DOCTYPE html>
<html>
<head>
    <style>
        /* .box {
            margin: 10px;
            column-count: 3;
            column-gap: 10px;
        }
        .item {
            margin-bottom: 10px;
        }
        .item img{
            width: 100%;
            height:100%;
        } */
        .box{
            column-count: 3;
            column-gap: 10px;
        }
        .item{
            margin-bottom: 20px;
        }
        .item img{
            width: 100%;
            height: 100%;
        }
    </style>
</head>
<body>
<div class="box">
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
    <div class="item">
        <img  src="mountain.jpg" alt="" />
    </div>
</div>
</body>
</html>
